3-d imaging assessment of scar formation and would healing in fat grafted vs non-fat grafted facial reconstruction wound sites

Conditions: Scar Formation; Autologous Fat Grafting

Summary: the purpose of this study is to assess scar-formation and wound healing following the use of autologous fat grafting in facial reconstruction patients. patients who have undergone facial reconstruction in the last 3 months will be randomized into two groups, one receiving fat grafting and one not receiving any intervention. these patients will continue to follow-up in our clinic for one year, with 3-d images taken at each follow-up visit to assess scar formation and wound healing. assessment of the scar will be undertaken by both healthcare personnel as well as general lay public. we hypothesize that patients undergoing fat grafting to the wound site will achieve a more aesthetically appealing result, with less scarring and improved wound healing as judged by both the general public and healthcare professionals.

a variety of local and regional skin flaps are used for reconstruction of skin defects on the face with the intention of full wound closure, healing, and scar minimization. scarring is an unavoidable consequence of wound healing, especially after significant facial reconstruction. fibroblasts migrate to the injurious site where they proliferate and deposit collagen. the collagenous proteins serve to fill in the wound defect and allow epithelial cells to accumulate and repopulate the skin surface. the collagenous base is subsequently exchanged for various types of collagen and is crosslinked. although scar formation is an important component of wound healing, patients develop scars differently based upon location and biology of the subject. excessive scar formation may result from excessive collagen production and inadequate collagen remodeling (gurtner). much effort has focused on minimizing scar formation. such techniques have included rigorous sterilization techniques, smaller, more linear incisions, and incisions that follow normal tension lines in the skin to name only a few. however, these techniques have been mostly limited to intraoperative or pre-operative measures. and while successful in minimizing scar burden, these techniques do not address scar management post operatively. wound healing and scar formation follow complex biological processes dependent on inflammatory cells and growth factors. it has been shown in utero that fetal wounds are capable of scarless healing during a phase of gestation when wounds heal with a paucity of inflammatory cells (soo, frantz). this principle was further studied in immune deficient mice lacking both macrophages and neutrophils, which are critical to the inflammatory response. within this experiment, both groups of mice (immunodeficient and normal mice) healed the wounds, the immunodeficient mice did so in a scarless manner (mori, martin). extrapolating this information to current surgical patients, the development of an immunomodulating measure is critical to inhibiting and managing scar formation. adipose derived mesenchymal stem cells (adscs) have been studied with regard to their role in the wound healing and scar formation process and have shown great promise. in experimental studies, adscs have shown to promote angiogenesis, granulation and reepithelialization of the overlying wound (ebrahimian). whether directly or indirectly through these processes, the adscs also improve the appearance of resultant scars by decreasing size, contrast of scar color, and improving pliability of the scar (blanton, yun). however, it is not to be confused that all adipose tissue is equivalent with adscs. rather, adscs are a particular line of cells found within adipose tissue that have the unique capability of differentiating into a variety of types of tissues, from bone to cartilage to further adipose tissue (zuk). these cells are capable of being harvested and cultured from adipose tissue within subjects and then subsequently injected into the wound site of interest. fat grafting is a similar but less involved technique that harvests autologous adipose tissue but does not use cell culture techniques to isolate adscs from other cell lineages. fat grafting has long been used as a technique concurrently with facial reconstruction procedures and facial rejuvenation procedures as a "filler" of sorts for facial augmentation as early as 1893 (miller). the fat injected into the face serves as a volume expander to correct defects related to loss of muscle or bone, such as in micrognathia. since those initial trials, the technique has been widely expanded and honed to provide the best possible contouring. in addition to the filler aspects and results of the procedure, the technique has been observed to improve skin quality in injection sites, improve pigmentation irregularities, and even improve appearance of long standing scars. however, a formal study of fat grafting's potential of improved wound healing and minimization of scar formation has never been undertaken. although not identical to the process of injection of autologous adscs, the process of fat grafting has the capabilities of providing some number of adscs that were in the adipose harvest. additionally, the process itself has been shown in the past to improve previously existing scars and improve the quality of skin overlying injection sites (coleman). therefore, it is logical to assume that injection of autologous fat will improve wound healing and minimize scar formation in patients undergoing the procedure through effects of adscs within the harvested tissue. with the advent of advanced 3-d imaging technology, we are now able to obtain high-quality, high-resolution images to document and detail stages of wound healing and scar formation. therefore, we will be able to determine through observer analysis whether the process of fat grafting changes the formation and quality of scars over time.

Eligibility criteria:
inclusion criteria: * healthy subjects * facial reconstruction surgery in the last 3 months exclusion criteria: * age less than 18 years * patients undergoing skin grafting * patients undergoing secondary intent closure

Keywords: scar fat grafting adipose grafting 3-d imaging manchester scar scale